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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
NASA NTRS1999

Fourth United States Microgravity Payload: One Year Report

This document reports the one year science results for the Fourth United States Microgravity Payload (USMP-4). The USMP-4 major experiments were on a support structure in the Space Shuttle's payload bay and operated almost completely by the Principal Investigators through telescience. The mission included a Glovebox where the crew performed additional experiments for the investigators. Together about eight major scientific experiments were performed, advancing the state of knowledge in fields such as low temperature physics, solidification, and combustion. The results demonstrate the range of quality science that can be conducted utilizing orbital laboratories in microgravity and provide a look forward to a highly productive Space Station era.

Ethridge, Edwin C.↗
NASA NTRS1999

Fourth United States Microgravity Payload: One Year Report

This document reports the one year science results for the Fourth United States Microgravity Payload (USMP-4). The USMP-4 major experiments were on a support structure in the Space Shuttle's payload bay and operated almost completely by the Principal Investigators through telescience. The mission included a Glovebox where the crew performed additional experiments for the investigators. Together about eight major scientific experiments were performed, advancing the state of knowledge in fields such as low temperature physics, solidification, and combustion. The results demonstrate the range of quality science that can be conducted utilizing orbital laboratories in microgravity and provide a look forward to a highly productive Space Station era.

Ethridge, E. C.↗
NASA NTRS2000

High Resolution Thermometry for EXACT

High Resolution Thermometers (HRTs) based on SQUID detection of the magnetization of a paramagnetic salt or a metal alloy has been commonly used for sub-nano Kelvin temperature resolution in low temperature physics experiments. The main applications to date have been for temperature ranges near the lambda point of He-4 (2.177 K). These thermometers made use of materials such as Cu(NH4)2Br4 *2H2O, GdCl3, or PdFe. None of these materials are suitable for EXACT, which will explore the region of the He-3/He-4 tricritical point at 0.87 K. The experiment requirements and properties of several candidate paramagnetic materials will be presented, as well as preliminary test results.

Panek, J. S.↗
NASA NTRS1980

Solid state crystal physics at very low temperatures

The properties of nearly perfect crystals was studied at cryogenic temperatures. A large Helium 3 and Helium 4 dilution refrigerator has been assembled, and is described. A cryostat suitable for cooling a 35 liter volume to .020 Kelvin was designed and constructed, together with instrumentation to observe the properties of nearly perfect crystals.

Davis, W.↗
NASA NTRS1980

Solid state crystal physics at very low temperatures

The mechanical dissipation (Q) and resonant frequency of a 15 kg silicon crystal were measured at cryogenic temperatures. In the experiment described, temperature control was incorporated to reduce the time derivative of the temperature. The results of the Q measurements with and without this temperature control are quite different. Measurements of the resonant frequency of the fundamental longitudinal mode of the silicon crystal from 6 to 300 Kelvin are presented and discussed with respect to temperature, df/dT. It is observed that frequency increases as temperature decreases down to about 16 Kelvin, i.e. dt/dT is negative. However, below this temperature the frequency decreases as temperature decreases, i.e. dt/dT is positive. It is suggested that this behavior is related to the coefficient of thermal contraction of silicon, which changes sign at 18 Kelvin. Continuation of these experiments to 20 mK is discussed.

Davis, W.↗
NASA NTRS2002

A low temperature facility for experiments on the International Space Station

The Jet Propulsion Laboratory (JPL) is currently developing the Low Temperature Microgravity Physics Experiments Facility (LTMPEF), a multiple user and multiple flight facility that will provide a long duration low temperature environment on board the International Space Station. The LTMPEF will be attached to the Japanese Experiment Module (KIBO) Exposed Facility of the International Space Station with an initial flight starting in late 2005. The LTMPF is a self contained, reusable, cryogenic facility containing a 180-liter superfluid helium tank, two experiment packages, and electronics to provide experiment control and telemetry. Two distinct primary experiments will be accommodated during each mission, and secondary experiments requiring no additional hardware beyond that built for the primary experiments will also be accommodated during each mission. Detailed technical capabilities of the Facility will be presented, along with a brief description of the six science investigations currently selected to fly on the first two missions.

International Space Station↗
NASA NTRS2003

Nonlinear Dynamics of the Superfluid Transition: What may We learn on orbit?

Linear response (specifically, Fourier's Law) in He-4 has been observed to fail in heat flow experiments near the superfluid transition. A detailed analysis of the data suggests that the hydrostatic pressure gradient across the helium column limits the divergence of the correlation length in our earth-based experiments. This is consistent with other observations, such as the surprising lack of mutual friction and hysteresis near the superfluid transition, and a 'rounding' of the transition that appears to be independent of heat flux in the low heat flux limit. I will discuss these unusual results from earth-based measurements, and will show predictions for the very different results that may result when we make our measurements on orbit as part of the M1 Mission of the Low- Temperature, Microgravity Physics Facility. This work has been funded by the Fundamental Physics Discipline within the Physical Sciences Research Office of NASA, and is conducted by the DYNAMX (UNM) and CQ (Caltech) Groups, with assistance from the Low Temperature Science and Quantum Sensors Group at JPL.

Duncan, Rob↗
DOE OSTI2025

Spatially resolved measurements of plasma ion velocity distributions in a dipole magnetic field

The equilibrium flows of a plasma discharge in a dipole magnetic field are a topic of interest in low temperature plasma physics. Experimentalists typically rely on probe-based and line-integrated diagnostic techniques in these environments to describe plasma behavior. Presented here are measurements of argon ion dynamics with laser induced fluorescence techniques to provide insight into plasma dynamics in dipole magnetic fields with nonperturbative, spatially localized measurements. Simulation results from a Lagrangian approach to track particle orbits are compared to measured density profiles and provide evidence to support the mechanism distinguishing experimental configurations is the initial approach of particles. Applying a negative DC bias to the magnet induces strong E×B flows around the magnet, even exceeding the ion acoustic speed as measured far from the magnet. A strong enough bias also produces two distinct ion populations and provides a method for controlling the density gradient on the equator.

McLaughlin, Jacob W. (ORCID:0000000152661888)↗
NASA NTRS1998

Measurements of the Plasma Parameters and Low Frequency Oscillations in the Fisk Plasma Source

A new plasma device, the Fisk Plasma Source (FPS), has been developed at Fisk University. This plasma device is used to study the physics of low temperature plasmas and plasma-material interactions. The FPS device is a stainless steel vacuum 6-way cross vacuum vessel with at 10-inch inner diameter. Low temperature argon plasmas are generated using DC glow discharge and thermionic filament techniques. Spatial profiles of the plasma density, plasma potential, and electron temperature are measured using Langmuir probes. We present initial experimental measurements of density and temperature profiles in the FPS device. Experimental and theoretical studies of low frequency oscillations observed in the FPS device are also presented.

Thomas, Edward, Jr.↗